PGPy 0.6.0 decrypts SED packets (typ 9). This is problematic,
because it allows attackers to downgrade SEIPDv1 (typ 18) packets
to SED packets, effectively stripping the authentication that
SEIPDv1 provides, making the ciphertext malleable, and allowing
EFAIL-style exfiltration attacks.
PGPy 0.6.0 decrypts SED packets (typ 9). This is problematic, because it allows attackers to downgrade SEIPDv1 (typ 18) packets to SED packets, effectively stripping the authentication that SEIPDv1 provides, making the ciphertext malleable, and allowing EFAIL-style exfiltration attacks.
https://www.metzdowd.com/pipermail/cryptography/2015-October/026685.html
To protect all SEIPDv1-encrypted messages, SED packets must not be decrypted.